Merge is a unified API platform that enables B2B software companies to add hundreds of integrations to their product through a single integration build. While not exclusively financial, Merge is widely used for accessing HRIS, payroll, accounting, ATS, and CRM data—making it essential infrastructure for fintech and HR-tech companies. Founded in 2020 and backed by Addition, NEA, and others, Merge allows product teams to integrate with Workday, ADP, QuickBooks, Salesforce, and 200+ other systems through one normalized API. For financial applications, Merge's Accounting category covers QuickBooks, Xero, NetSuite, Sage, and other accounting platforms with a unified data model for companies, accounts, transactions, invoices, and payments. The HRIS and Payroll categories provide employee and payroll data from ADP, Workday, BambooHR, and others—critical for financial apps embedding workforce cost analysis. Merge's Magic Link enables end users to authenticate their integrations securely. The platform handles OAuth flows, credential management, data normalization, and API version management, eliminating integration maintenance burden from product teams. Field Mapping allows customers to customize how their source system data maps to Merge's standard model. Analytics track integration health and usage. Merge has become infrastructure for hundreds of B2B SaaS companies that need rapid, scalable integrations without building each individually.